I had bought this machine back in May. It’s got a Pentium Core Duo, D 830 3ghz processor. And the motherboard is a ASUS P5ND2-SLI. It’s a very gaming-like machine, though I don’t do any gaming at all. I constantly run between 3-4 VMs on it though.

The important thing here, is something that had gone unnoticed when I built the machine. That the processor has this ‘feature’ called EM64T. And the motherboard supports it too. Well, the name is misleading part there. I thought it was just some fancy memory thingie. It means ‘Extended Memory 64 Technology’ (well, not anymore, now it has been renamed Intel 64).

Then I’ve learnt that this is actually Intel’s implementation of AMD64 technology. And that it can run Vista and XP 64.

So I’ve installed XP 64, which is also available as a trial (though I got mine from MSDN), and I must say that it feels much much faster. Whether that translates into real performance I can’t tell at the moment, but I plan to run some benchmarks. I still have the ‘old’ XP 32 installed on a separate disk.

Some interesting facts about XP 64:

It’s based on Windows 2003 SP1 codebase

It can run 32-bit applications just fine

This is because of a technology called WoW64 (Windows 32 on Windows 64). Zero noticeable speed impact.

It installs 32-bit applications in ‘\Program Files (x86)’ by default.

It installs registry keys on a ‘HKLM\Software\WoW6432Node’.

The last one is the most surprising. From what I can guess, when you run a 32-bit application it creates an environment that ‘hides’ the actual registry, and sets up some variables like %PROGRAMFILES% to point to different places. Very clever.

Now, a little confusion. When I went to download the 64-bit installer for Python 2.5, there are two options. ‘Itanium’ or ‘AMD64’. At that point I didn’t know that EM64T was equivalent to AMD64, so I tried the ‘Itanium’ installer. And to my surprise it did not install. But the AMD64 installer did work. I’ve reported that as a bug on the Python tracker.

So, since I’m running 64-bit now, I hope I can help with the transition, specially on pywin32, so that we can have a native 64-bit Zope installer sometime over the next year.